Investigation of the GeO2-1,6-Diaminohexane-Water-Pyridine-HF Phase Diagram Leading to the Discovery of Two Novel Layered Germanates with Extra-Large Rings

The systematic exploration of the phase diagram of the GeO2-1,6-diaminohexane-water-pyridine-HF system has allowed the identification of specific roles of the HF, H2O contents, and HF/H2O ratio in the formation of Ge7X19 (Ge7), Ge9X25−26 (Ge9), and Ge10X28 (Ge10) clusters (X = O, OH, F). This work has led to the discovery of two novel structures with extra-large 18-membered rings accommodating 1,6-diaminohexane (DAH): SU-63, |1.5H2DAH|[Ge7O14X3]·2H2O, a layered germanate constructed from Ge7 clusters with the Kagomé topology, and SU-64, |11H2DAH|[Ge9O18X4][Ge7O14X3]6·16H2O, a germanate built of two-dimensional slabs containing both Ge7 and Ge9 clusters (X = OH or F). We also put SU-64 in context with previously reported cluster germanate compounds with related topologies by means of a simple crystal deconstruction study.